1,4,8,11-tetrazacyclotetradecane-5,12-dione

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl acrylate (344 g, 4.0 moles) was added dropwise into neat ethylenediamine (240 g, 4.0 moles) while stirring. Addition was conducted at such a rate that the reaction temperature did not exceed 45° C. Addition time was 4.0 hours. The crude colorless product, N-(2-aminoethyl)-β-alanine methyl ester (580 g), was dissolved in deionized water to give a concentration of about 25 weight percent. Allowing the solution to stand at room temperature for 2-3 days caused a white solid product to slowly precipitate. The product was obtained as a fine white powder, m.p. 198° C.-199° C. Spectral analysis confirmed the product's structure as Addition did not exceed 45° C Addition time to give a concentration of about 25 weight percent to stand at room temperature for 2-3 days to slowly precipitate The product was obtained as a fine white powder, m.p. 198° C.-199° C

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl acrylate (344 g, 4.0 moles) was added dropwise into neat ethylenediamine (240 g, 4.0 moles) while stirring. Addition was conducted at such a rate that the reaction temperature did not exceed 45° C. Addition time was 4.0 hours. The crude colorless product, N-(2-aminoethyl)-β-alanine methyl ester (580 g), was dissolved in deionized water to give a concentration of about 25 weight percent. Allowing the solution to stand at room temperature for 2-3 days caused a white solid product to slowly precipitate. The product was obtained as a fine white powder, m.p. 198° C.-199° C. Spectral analysis confirmed the product's structure as --NHCH2CH2NHCH2CH2C(O)--2. Addition did not exceed 45° C Addition time to give a concentration of about 25 weight percent to stand at room temperature for 2-3 days to slowly precipitate The product was obtained as a fine white powder, m.p. 198° C.-199° C

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl acrylate (344 g, 4.0 moles) was added dropwise into neat ethylenediamine (240 g, 4.0 moles) while stirring. Addition was conducted at such a rate that the reaction temperature did not exceed 45° C. Addition time was 4.0 hours. The crude colorless product, N-(2-aminoethyl)-β-alanine methyl ester (580 g), was dissolved in deionized water to give a concentration of about 25 weight percent. Allowing the solution to stand at room temperature for 2-3 days caused a white solid product to slowly precipitate. The product was obtained as a fine white powder, m.p. 198° C.-199° C. Spectral analysis confirmed the product's structure as Addition did not exceed 45° C Addition time to give a concentration of about 25 weight percent to stand at room temperature for 2-3 days to slowly precipitate The product was obtained as a fine white powder, m.p. 198° C.-199° C

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl acrylate (344 g, 4.0 moles) was added dropwise into neat ethylenediamine (240 g, 4.0 moles) while stirring. Addition was conducted at such a rate that the reaction temperature did not exceed 45° C. Addition time was 4.0 hours. The crude colorless product, N-(2-aminoethyl)-β-alanine methyl ester (580 g), was dissolved in deionized water to give a concentration of about 25 weight percent. Allowing the solution to stand at room temperature for 2-3 days caused a white solid product to slowly precipitate. The product was obtained as a fine white powder, m.p. 198° C.-199° C. Spectral analysis confirmed the product's structure as --NHCH2CH2NHCH2CH2C(O)--2. Addition did not exceed 45° C Addition time to give a concentration of about 25 weight percent to stand at room temperature for 2-3 days to slowly precipitate The product was obtained as a fine white powder, m.p. 198° C.-199° C